An Israeli who rescued a distressed climber on Mount Everest during a chaotic period last weekend in which four climbers died on the mountain has said the man he rescued is like a brother to him.

Nadav Ben-Yehuda, 24, spoke of the encounter with Aydin Irmak, 46, in an interview with the Associated Press.

"Aydin, wake up! Wake up!" Ben-Yehuda recalled saying when he found his friend, an American of Turkish origin, in the darkness. Irmak, he said, had been returning from the summit but collapsed in the extreme conditions, without an oxygen supply, a flashlight and a rucksack.

The four people who died were also on their way down from the summit amid a traffic jam of more than 200 people who were rushing to reach the world's highest peak as the weather deteriorated.

Ben-Yehuda, who developed a friendship with Irmak before embarking on the climb, had delayed his own ascent by a day in the hope of avoiding the bottleneck of climbers heading for the top.

There have been periodic tales of people bypassing stricken climbers as they seek to fulfil a lifelong dream and reach the summit of Everest, but Ben-Yehuda said his decision to abandon his goal of reaching the top and help Irmak was "automatic", even though it took him several minutes to recognize his pale, gaunt friend.

"I just told myself, 'This is crazy.' It just blew my mind," Ben-Yehuda said. "I didn't realise he was up there the whole time. Everybody thought he had already descended."

The Israeli carried Irmak for hours to a camp at a lower elevation. Both suffered frostbite and some of their fingers were at risk of amputation. Ben-Yehuda lost 20kg in his time on the mountain, and Irmak lost 12kg, said Hanan Goder, Israel's ambassador in Nepal. Goder had dinner with the pair after their ordeal.

"They really have to recover mentally and physically," Goder said. "They call each other 'my brother'. After the event that they had together, their souls are really linked together now."

The Jerusalem Post, which reported that Ben-Yehuda would have been the youngest Israeli to reach Everest's summit, spoke to Irmak by telephone during the dinner that Goder hosted.

"I don't know what the hell is going on between the two countries," the newspaper quoted Irmak as saying. "I don't care about that. I talked to his [Ben-Yehuda's] family today and I told them you have another family in Turkey and America."

Ben-Yehuda, who spoke to AP just before leaving Nepal for urgent medical treatment in Israel, said he could not say with certainty how he would have reacted if he had come across a stricken climber he did not know. Oxygen is in such short supply and the conditions are so harsh, he said, that people on the mountain develop a kind of tunnel vision.

"You just think about breathing, about walking, about climbing," he said. According to Ben-Yehuda, the fundamental questions going through the mind of a climber heading for the peak are: "Are you going to make it?" and "When is the right time to turn back?"

And once a climber begins the descent, the all-embracing question becomes: "How fast can I go down?"